Description
TitleThe effect of mechanical stimulation on PEG-encapsulated mesenchymal stem cells
Date Created2017
Other Date2017-10 (degree)
Extent1 online resource (x, 55 p. : ill.)
DescriptionThe Effect of Mechanical Stimulation on PEG-Encapsulated Mesenchymal Stem Cells By: BROOKE MCCLARREN Thesis Advisor: Dr. Ronke Olabisi Human mesenchymal stem cells (hMSCs) are multipotent cells capable of differentiating into any mesenchymal tissue, including bone, cartilage, muscle, and fat. hMSC differentiation can be influenced by a variety of stimuli, including environmental and mechanical stimulation, including scaffold physical properties or applied loads. Numerous studies have evaluated the effects of vibration or tensile strain on MSCs but these studies generally use MSCs on tissue culture plastic or scaffolds derived from natural sources. Tissue culture plastic forces cells into a 2D monolayer in which they behave differently than in their native tissues and naturally sourced scaffolds have inherent biochemical and microarchitectural cues that also influence MSC fate. To isolate the effects of vibration and strain on hMSCs, polyethylene glycol diacrylate (PEGDA), a bioinert synthetic polymer hydrogel, was used to 3D encapsulate cells in hydrogel sheets. This Masters’ thesis expands on previous results where microencapsulated hMSCs were subjected to vibrations. Microencapsulated cells are subjected to vortexing and the surface tension caused by forming emulsion-based microdroplets. Hydrogel sheets were selected to eliminate the confounding factors introduced by the fabrication method, to standardize the encapsulation efficiency, and to enable the performance of tensile tests. hMSCs were entrapped in 10 kDa PEGDA hydrogel sheets, then subjected to 10% cyclic tensile strain, or 100 Hz vibrations at accelerations of 0.3, 3.0, or 6.0 g, for 24 hours. Following testing, entrapped cells were evaluated for viability and markers of differentiation at 1, 4, 7, 14, and 21 Days. Cells subjected to cyclic strain and cells subjected to accelerations of 0.3 g showed greater viability than control cells. hMSCs vibrated with accelerations of 3.0 g showed no change in viability compared to control while accelerations of 6.0 g were lethal to cells. Accelerations of 0.3 g also appeared to induce differentiation of encapsulated hMSCs along the osteogenic pathway. For vibration studies, these findings differed from previous findings with microspheres in that on day 4, 0.3 g microencapsulated cells exhibited alkaline phosphatase activity but cells in sheets did not. Additionally, 0.3 g cells encapsulated in hydrogel sheets exhibited mineral formation as early as day 7, while microencapsulated cells did not until day 14. These findings show the feasibility of using PEGDA as a scaffold for probing cell response to mechanical stimuli, and further demonstrate that the geometry of the scaffold selected can also influence hMSC fate.
NoteM.S.
NoteIncludes bibliographical references
Noteby Brooke McClarren
Genretheses, ETD graduate
Languageeng
CollectionSchool of Graduate Studies Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work.